A year after the curse's reversal, Hook restores her memories with a potion & they return to with Henry to save her family by breaking the new curse caused by Zelena, the Wicked Witch of the West. She finds an insane Neal trapped within Mr. Gold's body. Losing his mind, he asks for Emma to free his father by killing him to defeat Zelena; she reluctantly agrees. Regina later helps her to strengthen her magical powers, though they're removed when Zelena curses Hook but thanks to Regina they managed to defeat Zelena & close her time portal. After Emma & Hook're dragged into Zelena's time portal, she accepts Storybrooke as her home, regaining her magic to re-open the portal to the present where she begins a relationship with Hook. However, unaware to her, she also brings a previously deceased Maid Marian to the future which ruins Regina's happiness, having not heeded the warning of messing with the past. Elsa, who's trapped in an urn's also brought to Storybrooke by the time portal. While working with Elsa, who helps Emma to finally embrace & control her powers, Emma helps her new friend find her sister & return home while balancing the threat of the Snow Queen, who turns out to've been 1 of Emma's foster mothers, against her friends & family. After a period of peace, she begins to help Regina on her quest to find the Author of Henry's book. Cruella De Vil & Ursula soon come into town resurrecting Maleficent & working with Rumplestiltskin to find the very same author, intent on giving villains their happy endings. After Cruella De Vil threatens to kill Henry, Emma kills her, soon after learning of her parents' actions of removing Emma's potential for darkness by putting black magic within Maleficent's daughter & Emma's childhood friend Lily. She also learns that her entire life's controlled by destiny. After she returns to town, with encouragement from Hook she chooses to forgive her parents & let go of her anger. Later she's able to finally let her walls down & tells Hook she loves him. She then chooses to sacrifice herself for the town, asking her parents & Hook to save her, she voluntarily plunges the dagger into the Darkness, transforming into the new Dark One.
She searches for Merlin &'s helped by a manifestation of Rumplestiltskin, who wants to teach her to be the Dark One, while she attempts to resist becoming evil at the same time. Sometime later, she transformed Hook into a 2nd Dark One to save his life. He then cast the Dark Curse to get back to Storybrooke to've his revenge on Mr. Gold. Emma then altered the curse, adding a dreamcatcher in it to wipe out everyone's memories of their time in Camelot. 6 weeks later, the rest of her friends returned to Storybrooke, but with a horrifying & shocking twist, their memories' wiped out once again & wearing Arthurian attire. As it turned out she made an appearance as the Dark One, with her new attire. Henry asks what happened to her & she told them that they all went to Camelot to remove the darkness from her & they all failed; except Henry. Later her powers turned Sneezy into stone, proclaiming that there's no savior in the town that cast the surge of hope in everybody. She surprisingly gave the Dark One dagger to Regina with the intention that if she goes too dark Regina'd be the only 1 that'd willingly kill her. Shortly after this, Hook attempts true love's kiss with her in the hopes that the Dark One's curse'd break but ultimately failed as she'd fully embraced the darkness but unbeknownst to the others she currently's possession of the Excalibur in a locked room inside of her new house. She intends to make it & the Dark One's dagger whole again, as with it she'll be able to snuff out the light forever & become invulnerable. However, she must recruit a hero to do so, as she can't remove the sword; the hero she chooses' her predecessor Rumplestiltskin, who she tells finally has a chance to become a hero. She planned to siphon the darkness out of both of them & put it Zelena, who she forced into accelerated labor to avoid killing Robin's child & slay her. She regains her memories of what Hook plans, by resurrecting all the Dark Ones as part of his revenge. At 1st, she plans to absorb all the darkness inside her & kill herself. Things don't go according to plan when Hook steals it from her. Killian orders her to kill him, taking in all the darkness & she slays him with Excalibur while the darkness' removed from her, reverting to her old self. After blackmailing Mr. Gold for tricking her & Hook into making him the Dark One again, she, her friends & family descend into the Underworld to find Hook & plans to split her heart in ½ & share it with him like her parents.
Arriving in the Underworld, she's contacted by Neal, who warns to turn back, advice she chooses to ignore. She & the others later discover that the Underworld's for those with unfinished business & they decide to help others move on while they search for Hook. With the help of Hook's ex-girlfriend Milah, Emma manages to retrieve him from Hades' captivity. However, she's unable to split her heart, as Hades' decided that she, Regina & Snow're to remain behind for freeing the souls of Prince Henry, Hercules & Megara. It's discovered that the only way they'd've a chance to return to the "Overworld" with Hook's by overthrowing Hades. In order to defeat him, Emma & Hook receive help from Hook's brother Liam; however, it's soon discovered that Liam betrayed them after being blackmailed by Hades. Fortunately, Henry agrees to help undo Liam's work by using his powers as the Author. Later, when Emma & Hook try to perform the heartsplit, they're informed by Hades that Hook's body's been dead for too long &'s decaying, making him unable to come back to life. When Emma & Hook go into the depths of the Underworld to find ambrosia, something that'd save Hook, they're faced with a True Love test, which they pass when she chooses him over her own heart, only to realize that Hades' tricked them & destroyed the ambrosia & Hook tells Emma to leave him in the Underworld, as time's running out for her to go through the open portal. She objects, saying that she came to the Underworld to save him & she wasn't leaving without him. He eventually gets her to say her goodbyes & she does, only to find out that Hades' trapped her & her family in the library using magic. Emma & Regina work together to use their own magic to counteract it &, later, they all go through the portal, & while Emma's 2nd thoughts about leaving Hook, she's persuaded to go by her father. When they get back to Storybrooke, Zelena's informed by Regina & Robin that Hades tried to trap them in the Underworld but she brushes off the info &'s upset with her sister. She talks to Hades about having the life she wants, which's just a simple picket fence life. However, he wants a whole kingdom. Robin & Regina break into the mayor's house, where Zelena & Hades', trying to get Robin's daughter back from Zelena. Emma, distraught & unable to grieve Hook's death, tries to break down the protection spell surrounding the house but Zelena uses her magic to stop her. Hades' about to use the Olympian Crystal to "end" Regina, but Robin steps in front of her, taking the blow, which kills him. Hades tries to pressure Zelena into killing Regina but she kills him instead, as his love for her doesn't hold him back from being the villain he's.
